Threaded fasteners are known in the art for connecting one or more objects together. For example, a threaded fastener such as a nut, a stud, a screw, or a bolt may be used to join a series of rotor wheels together in a gas turbine application. The threaded fasteners are often heat stretched or pre-loaded to increase the amount of force holding the components together. However, experience and testing have shown that a relatively small portion of the threads at the end of the threaded fastener receive a majority of the load holding the components together, with the remainder of the threads of the threaded fastener relatively unloaded. As a result, larger fasteners are needed to achieve a desired holding force, resulting in increased manufacturing, maintenance, and repair costs.
Various efforts have been made to increase the load bearing capabilities of threaded fasteners. For example, the pitch or distance between adjacent threads may be reduced to increase the number of load bearing threads at the end of the threaded fastener. Alternately, or in addition, the effective diameter of the load bearing end of the threaded fastener may be reduced to distribute the load to threads further from the end. Nonetheless, additional improvements in the design of threaded fasteners would be desirable to improve the load distribution among the threads.